The only thing that I have come across is what is in the Satipatthana and some other suttas.

"There is the case where a monk — having gone to the wilderness, to the shade of a tree, or to an empty building — sits down folding his legs crosswise, holding his body erect and setting mindfulness to the fore [lit: the front of the chest]. Always mindful, he breathes in; mindful he breathes out.

“No lists of things to be done. The day providential to itself. The hour. There is no later. This is later. All things of grace and beauty such that one holds them to one's heart have a common provenance in pain. Their birth in grief and ashes.” - Cormac McCarthy, The Road

Learn this from the waters:in mountain clefts and chasms,loud gush the streamlets,but great rivers flow silently.- Sutta Nipata 3.725

The earliest source I know if is the text Ben shared although believe the commentary by Upotissa Thera "The Path of Freedom" has a more detailed description and would be the earliest post canonical work I know of.just checked the index and there isn't a more detailed description, must of been thinking of the visudhimagga.

Last edited by Cittasanto on Sun Nov 18, 2012 11:42 am, edited 1 time in total.

This offering maybe right, or wrong, but it is one, the other, both, or neither!Blog,-Some Suttas Translated,Ajahn Chah."Others will misconstrue reality due to their personal perspectives, doggedly holding onto and not easily discarding them; We shall not misconstrue reality due to our own personal perspectives, nor doggedly holding onto them, but will discard them easily. This effacement shall be done."

"Endowed with this noble aggregate of virtue, this noble restraint over the sense faculties, this noble mindfulness and alertness, and this noble contentment, he seeks out a secluded dwelling: a forest, the shade of a tree, a mountain, a glen, a hillside cave, a charnel ground, a jungle grove, the open air, a heap of straw. After his meal, returning from his alms round, he sits down, crosses his legs, holds his body erect, and brings mindfulness to the fore."